Liquid crystal display and method of manufacturing the same

ABSTRACT

There is provided an active matrix liquid crystal display having high reliability with improved yield of production. 
     In an active matrix liquid crystal display in which peripheral driving circuits are in contact with a liquid crystal material, spacers are dispersed in peripheral driving circuit regions in a density lower than that in a pixel region to reduce damage to the peripheral driving circuits and to improve production yield and reliability of products.

This is a continuation of U.S. application Ser. No. 08/767,316, filedDec. 16, 1996, now U.S. Pat. No. 5,815,231.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a configuration of an active matrixliquid crystal display having thin film transistors for pixels and thinfilm transistors for peripheral driving circuits on the same substrate.

2. Description of the Related Art

FIG. 4 shows a configuration of a panel forming a part of a conventionalactive matrix liquid crystal display. As apparent from FIG. 4, a pixelregion 404 has been enclosed by an opposite substrate 405 and a sealant402 (also referred to as “seal material”) while thin film transistors(hereinafter referred to as “TFT”) in peripheral driving circuit regions403 have been exposed to the atmosphere.

Therefore, it has been necessary to be very careful in handling, thesubstrate of an active matrix liquid crystal display at a panel assemblyprocess. Under such circumstances, there has been a need for aconfiguration of an active matrix liquid crystal display which makeshandling in manufacturing processes easier.

Further, the presence of the opposite substrate 405 above the pixelregion protects the pixel region 404 as a consequence. However, theperipheral driving circuits 403 are merely covered by a thin oxide filmand actually show weakness in anti-humidity characteristics and againstcontamination. Problems have arisen also in the aspect of reliability.

SUMMARY OF THE INVENTION

Methods were conceived to address such problems in which peripheraldriving circuits 403 of an active matrix liquid crystal display areconfigured to inhibit direct access thereto and, in which the regionwhere the opposite substrate resides is extended to the areas where theperipheral driving circuits are formed to include the peripheral drivingcircuits in a region where a liquid crystal material is present. Suchmethods are disclosed in Japanese patent application No. H7-50527(Japanese Laid-Open Aplication: H8-220560, Date of Laid-Open: Aug. 30,1996).

However, the following problems have arisen in such a configuration.

Among steps for assembling a liquid crystal display, a step of bondingtwo opposite substrates generally employs a process of hardening thesealant while applying a pressure vertically to the surfaces of thesubstrates. For a normal liquid crystal display, spacers are interposedbetween the two substrates to maintain a predetermined interval betweenthe two substrates. Therefore, a pressure is applied through the spacersto devices and the like formed on the substrates at this step.

Especially, in the case of a liquid crystal display having theconfiguration described above, the opposite substrate extending to theperipheral driving circuits has extended the pressure also to theperipheral driving circuits through the spacers.

In the peripheral driving circuit regions, TFTs are provided in adensity higher than that in the pixel region. Therefore, when thespacers are dispersed in a uniform density throughout the substrate asin conventional liquid crystal displays, the spacers cause more damagein the peripheral driving circuits than in the pixel region. Thisreduces reliability and yield.

In order to solve the above-described problems, according to the presentinvention, an active matrix liquid crystal display is configured asfollows.

Specifically, there is provided an active matrix liquid crystal displaywherein thin film transistors provided in a pixel region and thin filmtransistors provided in peripheral driving circuit regions reside on thesame substrate, characterized in that there is a difference in thedispersion density of spacers between the pixel region and theperipheral driving circuit regions.

As another configuration, there is provided an active matrix liquidcrystal display wherein thin film transistors provided in a pixel regionand thin film transistors provided in peripheral driving, circuitregions reside on the same substrate, characterized in that spacers arepresent in the pixel region and are not present in the peripheraldriving circuit regions.

When an active matrix liquid crystal display is configured such thatthin film transistors disposed in a pixel region and thin filmtransistors forming peripheral driving circuit regions of an activematrix liquid crystal display are integrated on the same substrate, inthe above-described configuration, a mask is provided in the regionswherein the TFTs for the peripheral driving circuit regions reside whenthe spacers are dispersed to inhibit the spacers from being dispersedtherein to improve the reliability of the peripheral driving circuits,thereby improving the yield of the peripheral driving circuits.

In a case that a means utilizing static electricity is used as a methodof dispersing spacers, better methods for applying a voltage forgenerating static electricity are pursued. For example, when spacers aredispersed to improve the reliability of peripheral driving circuits, thespacers are dispersed in a lower density in the regions where the TFTsfor the peripheral driving circuits reside by applying a voltage at avalue different from that applied to the region where pixel TFTs resideto improve the yield of the peripheral driving circuits.

Further, when the spacers are dispersed, the dispersion density of thespacers is made lower in the regions on the stage carrying thesubstrates of an active matrix liquid crystal display where the TFTs forthe peripheral driving circuits reside by applying a voltage thereto ata value different from that applied to the region where the pixel TFTsreside, thereby improving the yield of the peripheral driving circuits.Alternatively, when the spacers are dispersed, the voltage forgenerating static electricity is not applied to the regions where theTFTs for the peripheral driving circuits reside and the potential forgenerating static electricity is applied only to the region where thepixel TFTs reside. This allows the spacers to be selectively dispersedonly in the pixel region. Further, the density of the spacers dispersedin the peripheral driving circuit regions may be reduced.

When peripheral driving circuit regions are included in a region whereinliquid crystals are present, damage to the TFTs forming the peripheraldriving circuits caused by the presence of spacers is reduced bylowering the density of the spacers dispersed in the peripheral drivingcircuit regions or by inhibiting the spacers from being dispersed in theperipheral driving circuit regions. Thus, it is possible to improve thereliability of a liquid crystal display having a configuration wherein apixel region and peripheral driving circuits are formed on the samesubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a method of dispersing spacer in a firstembodiment of the present invention.

FIG. 2 schematically shows a method of dispersing spacers in a secondembodiment of the present invention.

FIG. 3 is a sectional view of an active matrix liquid crystal display ofthe first embodiment of the present invention.

FIG. 4 schematically shows a conventional active matrix liquid crystaldisplay.

FIGS. 5A through 5E show steps of producing TFTs in the first embodimentof the present invention.

FIG. 6 is a sectional view of an active matrix liquid crystal display ofa third embodiment of the present invention.

FIG. 7 is a view illustrating a state of spacers on a TFT substratedispersed using a method in the first embodiment of the presentinvention.

FIG. 8 is a sectional view of an active matrix liquid crystal display ofa fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First Embodiment

Steps of assembling an active matrix liquid crystal display according tothe present embodiment will be described below.

In the present embodiment, no-alkali glass is used as a substrate.First, a pixel region having a matrix-shaped configuration andperipheral driving circuits for driving the pixel region are provided onthis glass substrate using a well known method or an appropriate method.In the pixel region, at least one thin film transistor as a switchingdevice is provided on each of pixel electrodes provided in a quantity onthe order of several hundreds by several hundreds.

In the peripheral driving circuit regions, circuits for driving the thinfilm transistors provided in the pixel region are configured using thinfilm transistors. As the peripheral driving circuits, shift registersand address decoders are used.

Each of the TFT substrate and a color filter substrate is subjected tocleaning to sufficiently remove various chemicals such as an etchant andresist remover used for surface treatment.

Next, orientation films are formed on the substrate having TFTs formedthereon (hereinafter referred to as “TFT substrate”) produced using themethod described above and a substrate having a color filter formedthereon (hereinafter referred to as “color filter substrate”). Theorientation films are formed from a material obtained by dissolvingpolyimide by approximately 10% by weight in a solvent such as butylcellosolve, n-methyl-2-pyrolidone, or γ-butyrolactone. This is referredto as polyimide varnish. In this embodiment, AL-3046 available fromNIPPON SYNTHETIC RUBBER CO. LTD. is used as polyimide varnish burned atlow temperatures. The polyimide varnish is applied to the substratesusing methods such as the use of a spinner and printing using aflexographic printing apparatus or screen printing apparatus.

Then, the orientation films applied to both of the TFT substrate andcolor filter substrate are heated and hardened (baked). In the presentembodiment, the baking is carried out through heating by feeding hot airat 180° C. to burn and harden the polyimide varnish.

Next, a rubbing step is performed wherein the surfaces of the glasssubstrates having the orientation films formed thereon are rubbed bybuff cloth with hairs having a length of 2 to 3 mm (fiber such as rayonand nylon) in a predetermined direction to form microscopic grooves.Spacers are then dispersed on the TFT substrate. The method ofdispersing the spacers will be described later.

Next, a sealant is applied to an outer frame of the TFT substrate. Thepurpose of the application of the sealant is to bond the TFT substrateand the color filter substrate and to prevent a liquid crystal materialinjected from being leaking to the outside. A material obtained bydissolving epoxy resin and a phenolic hardener in ethyl cellosolve maybe used as the sealant.

The two glass substrates are laminated after applying the sealant. Thelaminated TFT substrate and color filter substrate are pressed for threehours at 160° C. to heat and harden the sealant, whereby the TFTsubstrate and the color filter substrate are bonded and secured.

Finally, a liquid crystal material is injected from a liquid crystalinjection port of a resultant liquid crystal panel formed by laminatingthe TFT substrate and the color filter substrate and, thereafter, theliquid crystal injection port is sealed with epoxy type resin. Thus, anactive matrix liquid crystal display is assembled.

A method of dispersing the spacers will now be described with referenceto FIG. 1. First, the spacers are dispersed on a display region of asubstrate 101. Plastic spacers (Micropearl manufactured by SEKISUI FINECHEMICAL CO. LTD.) having a diameter of 5.0 μm are used as the spacers.The spacers are transported in nitrogen gas and dispersed in a duct 104.The spacers are ejected onto the substrates from a dispersing nozzle 105provided on the ceiling of a chamber 106 of a dispersing machine. Thenozzle is secured to the ceiling with rubber packing and its end ismovable in all directions. When the spacers are dispersed, the nozzle isswung in all directions to disperse the spacers uniformly on thesubstrates. The amount of the spacers dispersed is adjusted to achievean average dispersion density of 100 pcs./mm².

In order to inhibit the spacers from being dispersed in the areas ofperipheral driving circuit regions, as shown in FIG. 1, a mask 102 isdisposed above the substrate 101 during dispersion so that it does notcontact with the substrate. As shown in FIG. 1, the mask is formed withholes 103 in areas excluding those corresponding to the drivingcircuits. The shape of the holes is 52 mm×16 mm in a locationcorresponding to the area of source drivers and 8 mm×80 mm in a locationcorresponding to the area of gate drivers. The interval between thesubstrate and the mask is 1 mm.

Steps of producing the active matrix circuit of the present inventionwill now be described with reference to FIGS. 5A through 5E. Steps ofproducing the TFTs for the peripheral driving circuits are shown on theleft side of the figure and steps of producing the TFTs for the activematrix circuit are shown on the right side of the figure.

First, a silicon oxide film having a thickness of 1000 to 3000 Å isformed on a non-alkali glass substrate (a quartz substrate may be usedinstead) 501 as a base oxide film 502. This silicon oxide film may beformed using a sputtering or plasma CVD process in an oxygen atmosphere.

Next, an amorphous or polycrystalline silicon film is formed using aplasma CVD or LPCVD process to a thickness of 300 to 1500 Å, preferably500 to 1000 Å. The silicon film is then crystallized by performingthermal annealing at a temperature equal to or higher than 500° C.,preferably in the range of 800 to 950° C.

The crystallization through thermal annealing may be followed by opticalannealing to obtain higher crystallinity. During, the crystallizationthrough thermal annealing, an element such as nickel for promotingcrystallization of silicon (catalytic element) may be added as describedin Japanese Laid-Open Patent Application (KOKAI) Nos. H6-244103 andH6-244104.

The silicon film is then etched to form active layers 503 (for P-channeltype TFTs) and 504 (for N-channel type TFTs) of TFTs for the peripheraldriving circuits and an active layer 505 of TFTs for the matrix circuit(pixel TFTs) in the form of islands. Further, a sputtering process isperformed in an oxygen atmosphere to form a silicon oxide gateinsulation film 506 having a thickness of 500 to 2000 Å. The gateinsulation film may be also formed using a plasma CVD process. When thesilicon oxide film is formed using a plasma CVD process, it ispreferable to use dinitrogen oxide (N₂O) or oxygen (O₂) and mono-silane(SiH₄) as material gasses.

Thereafter, a polycrystalline silicon film (including a very smallamount of phosphorus for improving conductivity) having a thickness of2000 Å to 5 μm, preferably 2000 to 6000 Å is formed on the entiresurface of the substrate using an LPCVD process. Then, etching isperformed to form gate electrodes 507, 508 and 509 (FIG. 5A).

Thereafter, an ion doping process is performed to implant impurity ionson a self-alignment basis into all of the island-shaped active layersusing the gate electrodes as a mask. Here, phosphorus is implanted usingphosphine (PH₃) as a doping gas. The dose is 1×10¹² to 5×10¹³ atoms/cm².As a result, weak N-type regions 510, 511 and 512 are formed (FIG. 5B).

Next, there is formed a photoresist mask 513 covering the active layer503 of the P-channel type TFTs and a photoresist mask 514 covering apart of the active layer 505 of the pixel TFTs which is parallel to thegate electrode and extends to a position 3 μm off the edges of the gateelectrode 509.

Then, an ion doping process is performed again to implant phosphorususing phosphine as a doping gas. The dose is 1×10¹⁴, to 5×10¹⁵atoms/cm². As a result, strong N-type regions (source/drain) 515 and 516are formed.

No phosphorus is implanted during this doping in regions 517 covered bythe mask 514 of the weak N-type region 512 of the active layer 505 ofthe pixel TFTs. Therefore, those regions remain weak N-type (FIG. 5C).

Next, the active layers 504 and 505 of the N-channel type TFTs arecovered with a photoresist mask 518, and an ion doping process isperformed to implant boron in the island-shaped region 503 usingdiborane (B₂H₆) as a doping gas. The dose is 5×10¹⁴ to 8×10¹⁵ atoms/cm².Since the dose of boron in this doping exceeds the dose of phosphorusshown in FIG. 5C, the previously formed weak N-type region 510 isinverted into a strong P-type region 519.

The above-described doping processes form the strong N-type regions(source/drain) 515, 516, strong P-type region (source/drain) 519, andweak N-type regions (low density impurity region) 517. In the presentembodiment, the width x of the low density impurity regions 517 isapproximately 3 μm (FIG. 5D).

Thereafter, thermal annealing is carried out for 0.5 to 3 hours at 450to 850° C. to allow recovery from damage caused by doping to activatethe doped impurities, and to allow recovery of the crystallinity ofsilicon. Then, a silicon oxide film having a thickness of 3000 to 6000 Åis formed on the entire surface using a plasma CVD process as a layerinsulator 520. This may be a silicon nitride film or a multilayer filmconsisting of a silicon oxide film and a silicon nitride film. The layerinsulator 520 is then etched using a wet etching process to form acontact hole in the source and drain.

A sputtering process is then performed to form a titanium film having athickness of 2000 to 6000 Å which is in turn etched to formelectrodes/lines 521, 522 and 523 for the peripheral circuits andelectrodes/lines 524 and 525 for the pixel TFTs. Further, a plasma CVDprocess is performed to form a silicon nitride film 526 having athickness of 1000 to 3000 Å as a passivation film which is then etchedto form a contact hole which reaches the electrode 525 of the pixel TFT.

Finally, an ITO (indium tin oxide) film having a thickness of 500 to1500 Å formed using a sputtering process is etched to form a pixelelectrode 527. Thus, the peripheral logic circuit and active matrixcircuit are integrally formed (FIG. 5E).

FIG. 3 is a sectional view of the active matrix liquid crystal displayproduced in the present embodiment. In FIG. 3, a transparent electrode305 and an orientation film 306 are formed on one side of a TFTsubstrate 302 and a polarizing plate 301 is provided on the other side.

Further, a color filter 304, a transparent electrode 305 and anorientation film 306 are formed on one side of a color filter substrate303, and a polarizing plate 301 is provided on the other side.

A liquid crystal material 310 is sandwiched by the above-described twosubstrates, and spacers 307 for maintaining a predetermined intervalbetween the two glass substrates are present in the liquid crystalmaterial in dispersion densities which depend on regions. In the presentembodiment, the dispersion density of the spacers in the peripheraldriving circuit region 309 is 0. FIG. 7 shows the region on the TFTsubstrate where the spacers are dispersed. In the present embodiment, nospacer is present in peripheral driving circuit regions 309, and thespacers are present only in other regions (the area indicated by obliquelines in the figure). The average dispersion density of the spacers in apixel region 701 is 100 pcs./mm².

The TFT substrate and the color filter substrate are bonded by a sealant311.

Although not shown, a shading film such as a chromium or aluminum filmfor blocking light must be formed on the upper surface of the peripheraldriving circuit regions.

Because the spacers are not dispersed on the peripheral drivingcircuits, the liquid crystal display formed as described above exhibitsvery high strength against an external pressure and can sufficientlyprotect the peripheral driving circuits from breakage.

Second Embodiment

This embodiment is identical to the first embodiment except the methodof dispersing the spacers. Therefore, only the method of dispersion willbe described with reference to FIG. 2.

First, the spacers are dispersed on the display region of the substrate101. The spacers are dispersed using the sam dispersing machine as thatused in the first embodiment.

Plastic spacers having a diameter of 5.0 μm (Micropearl manufactured bySEKISUI FINE CHEMICAL CO. LTD.) are used as the spacers. The spacers aretransported by nitrogen gas and dispersed in the duct 104. The spacersare naturally charged as a result of friction with the duct duringtransportation.

In order to inhibit the spacers from being dispersed in the area of thedriving circuits, as shown in FIG. 2, a mask 202 is provided above thesubstrate 101 during dispersion such that it, does not contact with thesubstrate. The mask 202 is formed with holes in areas excluding thosecorresponding to the driving circuits. The shape of the holes is thesame as that in the first embodiment. The interval between the substrateand the mask is 1 mm. Further, a conductive material such as a metal isused for the mask to allow a DC electric field to be applied between themask and the stage. The potential of the mask is made the same as thatof the spacers with the stage carrying the substrate serving as areference. In the present embodiment, a voltage of −1 kV is applied.

FIG. 7 shows the region on the TFT substrate where the spacers aredispersed. In the present embodiment, no spacer is present in theperipheral driving circuit regions 403 and the spacers are present onlyin other regions (areas indicated by oblique lines). The averagedispersion density of the spacers is 100 pcs./mm².

Because the spacers are not dispersed on the peripheral drivingcircuits, the liquid crystal display formed as described above exhibitsvery high strength against an external pressure and can sufficientlyprotect the peripheral driving circuits from breakage.

Third Embodiment

The present embodiment shows a method for achieving a cell thickness ofhigher uniformity at steps of assembling an active matrix liquid crystaldisplay using the method of dispersing spacers in the first or secondembodiment. FIG. 6 schematically illustrates the present embodimentwhich is identical to the first or second embodiment except the methodof dispersing spacers.

Plastic spacers having a diameter of 5.5 μm (Micropearl manufactured bySEKISUI CHEMICAL CO. LTD.) 601 are mixed in a sealant 311 for bondingthe TFT substrate 302 and color filter substrate 303 obtained in thesame manner as in the first or second embodiment and for preventing aliquid crystal material injected therein from leaking to the outside. Atthis time, the sealant is inhibited from covering the peripheral drivingcircuit 309. Further, the spacers are not limited to the above-mentionedplastic material in this case and, for example, glass, silica or thelike may be used.

Next, the substrate 302 and the color filter substrate 303 are laminatedand the bonding material is hardened.

Thereafter, the laminated substrates as a whole are put in adecompressed state, and the liquid crystal material 310 is injected andsealed in the display region.

In a liquid crystal display formed as described above, the cellthickness between the TFT substrate 302 and the color filter substrate303 can be made uniform to obtain preferable display characteristicshaving no color variation. Further, since the spacers are not dispersedon the driving circuit, it exhibits very high strength against anexternal pressure and can sufficiently protect the peripheral drivingcircuits from breakage.

Fourth Embodiment

The present embodiment shows an arrangement to manufacture a pluralityof devices from a pair of glass substrates by dividing a active matrixliquid crystal display as described above using the sealant into aplurality of parts during steps of assembling an active matrix liquidcrystal display using the method of dispersing spacers according to thefirst or second embodiment. The present embodiment is identical to thefirst embodiment except the method of dispersing the spacers.

In the present embodiment, a plurality of sets of active matrix displaysubstrates as shown in the first embodiment are configured using a pairof large glass substrates. FIG. 8 shows an example of such aconfiguration. In FIG. 8, four sets of active matrix display substratesas shown in the first embodiment are configured on the large substrates.The configurations of elements of a pixel region 804 and peripheraldriving circuits 803 of each set are the same as those in the firstembodiment.

In the present embodiment, as shown in FIG. 8, one substrate is dividedinto four parts. The sealant used in this embodiment is the same as thatin the first embodiment. Further, the present embodiment employs largeglass substrates. In order to make the cell thickness more uniform, theplastic spacers as described in the third embodiment are mixed with thesealant.

The mask used in this case has the holes corresponding to the peripheraldriving circuit regions as described in the first and second embodimentswhich are formed in correspondence to the plurality of sets ofperipheral driving circuit regions. FIG. 8 shows the area on the TFTsubstrates in which the spacers are dispersed when such a mask is used.As in the first and second embodiments no spacer is present in theperipheral driving circuit regions 803 and the spacers are present onlyin other regions (the area indicated by oblique lines in the figure).The average dispersion density of the spacers is 100 pcs./mm².

The sealant is heated and hardened and, thereafter, grooves defining thesize of panels are cut in the glass substrates using a scriber. Then, around member made of urethane is dropped by the pressure of an aircylinder from directly above the grooves on the substrates using abreaker to divide the thin film transistor substrates into a pluralityof parts in the size of panels.

Finally, a liquid crystal material is injected from an liquid crystalinjection port of each of the active matrix liquid crystal displaysconsisting of the TFT substrate and the color filter substrate laminatedtogether and, thereafter, the liquid crystal injection port is sealedwith epoxy type resin. Thus, a plurality of active matrix liquid crystaldisplays having a more uniform cell thickness can be producedsimultaneously.

By dispersing spacers in peripheral driving circuit regions in a densitylower than that in a pixel region, damage to the peripheral drivingcircuits caused by the spacers can be reduced and the yield of theperipheral driving circuits can be improved.

What is claimed is:
 1. A method of manufacturing a liquid crystaldisplay device comprising: preparing a first substrate for forming atleast a first liquid crystal panel and a second liquid crystal panel;forming a first active matrix circuit and a first driver circuit forsaid first liquid crystal panel and a second active matrix circuit and asecond driver circuit for said second liquid crystal panel over saidfirst substrate, respectively; disposing a first sealing member forsurrounding said first active matrix circuit and said first drivercircuit and a second sealing member for surrounding said second activematrix circuit and said second driver circuit over said first substrate,respectively; disposing first spacers over said first substrate; matinga second substrate to said first substrate with said first and secondsealing members and said first spacers therebetween; and cutting saidfirst and second substrates into at least the first liquid crystal paneland the second liquid crystal panel, wherein a distribution density ofsaid first spacers over said first and said second active matrixcircuits is different from a distribution density of said first spacersover said first and second driver circuits, and wherein a portion ofsaid first spacers are disposed in an interval of said first and saidsecond liquid crystal panels.
 2. A method according to claim 1, whereinsaid first and second sealing members are mixed with second spacers. 3.A method according to claim 1, wherein said first spacers are notdisposed over said first and second driver circuits.
 4. A methodaccording to claim 1, further comprising introducing liquid crystalmaterials into said first and second liquid crystal panels after saidcutting.
 5. A method of manufacturing a liquid crystal display devicecomprising: preparing a first substrate for forming at least a firstliquid crystal panel and a second liquid crystal panel; forming a firstactive matrix circuit and a first driver circuit for said first liquidcrystal panel and a second active matrix circuit and a second drivercircuit for said second liquid crystal panel over said first substrate,respectively; disposing a first sealing member for surrounding saidfirst active matrix circuit and said first driver circuit and a secondsealing member for surrounding said second active matrix circuit andsaid second driver circuit over said first substrate; disposing spacersover said first substrate wherein each of said first and second sealingmembers is provided with at least one inlet port for introducing aliquid crystal material therefrom; mating a second substrate to saidfirst substrate with said first and second sealing members and saidspacers therebetween; and cutting said first and second substrates intoat least the first liquid crystal panel and the second liquid crystalpanel, wherein a distribution density of said spacers over said firstand said second active matrix circuits is different from a distributiondensity of said spacers over said first and second driver circuits, andwherein a portion of said spacers are disposed in an interval of saidfirst and said second liquid crystal panels, and each of the first andsecond active matrix circuits is disposed between the associated inletport and corresponding one of the first and second driver circuits.
 6. Amethod according to claim 5, further comprising introducing liquidcrystal materials into said first and second liquid crystal panelsthrough the respective inlet port after said cutting.
 7. A method ofmanufacturing a liquid crystal display device comprising: preparing afirst substrate for forming at least a first liquid crystal panel and asecond liquid crystal panel; forming a first active matrix circuit and afirst driver circuit for said first liquid crystal panel and a secondactive matrix circuit and a second driver circuit for said second liquidcrystal panel over said first substrate, respectively; disposing a firstsealing member for surrounding said first active matrix circuit and saidfirst driver circuit and a second sealing member for surrounding saidsecond active matrix circuit and said second driver circuit over saidfirst substrate, respectively; disposing spacers on said firstsubstrate; mating a second substrate to said first substrate with saidfirst and second sealing members and said spacers therebetween; andcutting said first and second substrates into at least the first liquidcrystal panel and the second liquid crystal panel, wherein each of saidfirst and second active matrix circuits comprises a thin film transistorhaving an active layer, a gate electrode, and a gate insulation filmtherebetween, wherein a distribution density of said spacers over saidfirst and said second active matrix circuits is different from adistribution density of said spacers over said first and second drivercircuits, and wherein a portion of said spacers are disposed in aninterval of said first and said second liquid crystal panels.
 8. Amethod according to claim 7, wherein said thin film transistor is atop-gate type thin film transistor.
 9. A method according to claim 7,wherein said gate electrode comprises polycrystalline silicon.
 10. Amethod according to claim 7, further comprising forming a base film onsaid first substrate.
 11. A method according to claim 10, wherein saidbase film comprises silicon oxide.
 12. A method according to claim 7,wherein said active layer has a pair of low density impurity regionsadjacent to source and drain regions.
 13. A method according to claim 7,wherein said gate insulation film comprises silicon oxide.
 14. A methodaccording to claim 7, wherein said active layer comprises crystallizedsilicon.